1. Field of the Invention
The present invention is directed to a lightweight air coupler for an air seeder comprising an aluminum frame that is die cast around steel sleeves having a knurled surface.
2. Description of the Prior Art
Air seeders are commonly towed by tractors to apply seed and/or fertilizer to a field. Typically, the air seeder is towed in combination with a tilling implement, one behind the other. The seed cart carries seed and fertilizer and directs measured amounts of these products through air lines to ground openers on the tilling implement. The ground openers place seed and fertilizer under the surface of the soil. The seed cart comprises one or more frame-mounted product tanks for holding granular product, such as seed and/or fertilizer. The seed cart is provided with a product meter located below the product tanks for dispensing metered product from the respective product tank into a pneumatic distribution system for delivering the metered product to the field. The pneumatic distribution system comprises a plurality of air lines that extend rearwardly from the product meters to secondary air distribution manifolds located on the tilling implement. Each air line comprises a seed cart air line and a tilling implement air line that are coupled to one another at a coupler. The secondary air distribution manifolds (xe2x80x9cheadersxe2x80x9d) distribute product through individual lines to seed boots mounted behind ground openers on the tilling implement.
The tilling implement is detachably coupled to the seed cart by a hitch. The air lines from the seed cart extend rearwardly to a coupler mounting on the tilling implement. The seed cart air lines are detachably mounted to the coupler. Tilling implement air lines are fixed to the coupler and extend to the secondary air distribution manifolds. That portion of the seed cart air lines adjoining the coupler typically comprise flexible tubes. Pairs of these tubes are mounted to a detachable air coupler. The detachable air coupler is mounted to a vertical standard fixedly mounted on the tilling implement. When mounted to the vertical standard the seed cart air lines are coupled to corresponding tilling implement air lines. The air couplers are held in place on the vertical standards by a mechanical latch.
Typically air couplers are made of steel. Steel air couplers and the seed cart air lines to which they are mounted are very heavy and clumsy to attach and detach from the vertical standard. Aluminum air couplers have also been used to reduce the weight of the air coupler facilitating attachment and detachment to and from the vertical standard. However, it has been found that the high speed air stream and associated seed and fertilizer can erode the aluminum air coupler at unacceptable rates.
It is an object of the present invention to provide a lightweight air coupler having an aluminum frame and steel sleeves.
A lightweight detachable air coupler for an air seeder comprises an aluminum frame having two steel sleeves die cast into the frame. The frame is provided with two circular apertures each being defined by a rim having an internal cylindrical surface. The steel cylindrical sleeve has a first end having an exterior surface that is diagonally knurled. Two steel sleeves are mounted in the mold for the aluminum frame and cast aluminum is injected into the mold. The liquid aluminum adheres to the knurled exterior surface of the steel sleeves. The aluminum frame has a front surface from which the rims project and a rear surface from which the sleeves project.